Starting-valve.



No. 892,194. PATENTED JUNE 30, 1908. A'. STEWART, J. MOGLUSKBY & H. G. REID.

STARTING VALVE.

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UNITED 'sTATEsJlITENT oEEioE ADAM STEWART, JAMES TNICCLUSKEY, AND HERBERT GATES REID, OF NORTH BAY, ONTARIO, CANADA.

STARTING-VALVE.

Specication of Letters Patent.

Patented June 30, 1908.

Application filed October 18, 1906. Serial No. 339,585.

To all whom fit may concern:

Beit known that we, ADAM STEWART, machinist, J AMES TNICOLUSKEY, engineer, and HERBERT GATES REID, engineer, all ol the town of North Bay, in the district ol Nipissing, Province of Ontario, Canada, have invented certain new and useful Improvements in Starting-Valves, oi which the following is the specification.

Our invention relates to improvements in emergency exhaust valves for locomotives,l

and the object of the invention is to provide a valve of this class which will not be liable to get out of order by reason of the head becoming detached from the valve stem and in which the head when not in use will work easily in the cylinder without any wear and will only become tight at the end or working point ol the stroke and it consists essentially of a cylindrical head provided with an enlarged outer end having an inclined inner face and a reduced threaded inner end, an expanded ring having an inclined outer iace surrounding the body of the head, a vpair of split rings interposed between the expander ring and the enlarged portion of the head and having inclined faces designed to coact with the inclined face of the expander ring and inclined face of the head, a locking device for the expander ring and nuts located in the valve stem to each side of the head, as hereinafter more particularly explained in the following specification.

Figure l is a sectional view through a portion of the engine showing the valves arranged for working the engine on single expansion. Fig. 2 is a similar view to Fig. l

showing the valves arranged for working the engine at compound. Fig. 3 is an enlarged sectional detail of the emergency exhaust valve head shown in the single expansion position. Fig. 4 is a similar view to Fig. 3 showing the valve head at the compound position. Fig. 5 is an enlarged perspective detail of the emergency exhaust valve head. Fig. 6 is a longitudinal section through the emergency exhaust valve head. Fig. 7 is a detail of the locking bars.

In drawings like letters of reference indicate corresponding parts in each iigure.

A is the frame of the engine, B is the receiver pipe connecting the high and low pressure cylinders, C the steam inlet, D the intercepting valve, E the exhaust to the atmosphere.

F is a passage leading into the exhaust E.

G is the emergency exhaust valve operating in the chamber G having a shoulder 2.

His a steam or air 'lilled pipe controlled by a valve in the cab o'l the engine.

When it is desired to work the engine at simple air is admitted into the chamber G forcing the valve G open and allowing steam to exhaust through the passage F, from the receiver B to the atmosphere.

I is a valve stem of the emergency exhaust valve and K is the inner or piston head of the valve.

It has been found that by the use oi the old -form of piston or valve head where the expander rings are in contact with the internal surface of the casing ior the full length of the stroke that the casing becomes worn into the form indicated by dotted lines in Figs. 3 and 4 on account ol' thcrings sticking at the beginning of the stroke. I/Vhen the valve becomes worn and a new one inserted it will not fit the casing at this part and will allow air to leak past to such an extent that the air pump will either become worn out in compensating for such leakages or the valve will not operate. If the air ressure cannot be kept u the engine has to e run in compound while c rifting that is when the engine is running down hill with the steam shut off, and in consequence burns as much coal drifting as when running under steam. Also in the old form the nut J 3 securing the piston to the valve is liable to break off and the compression spring of the valve would then force the4 head oil the stemrendering the valve inoperative. To overcome these objections we have devised a special form oi piston head, which we will now describe.

J is a nut secured on the valve stem I and provided with a shoulder J.

K is the com ression spring of the valve which is locater between the valve casing and the nut and surrounding the stem o'l the valve.

K is the head provided with the enlarged portion L/ having a beveled or inclined face L2. The head L is also provided with a reduced threaded portion L3.

L4 is a split ring having a flat face L5 and an inner beveledor inclined face L designed outer inclined face L11 designed to contactv With the inclined face L9 of the split ring L7.

M is an internally threaded holding ring designed to screw onto the reduced portion of the head and partially overlap the inner face of the expander ring yL10 to hold the same on the head.

N is a locking bar provided With a threaded stem N and a in N2.

N3 is an interna y threaded hole formed in the end of the head and N4 is a hole formed Eartially in the head and partially in the oldinfr ring M. The stem N is screwed into the hole N3 and the pin N 2 is then sprung into place into the hole N 4. By this Lmeans the holding ring is securely locked in place.

Having described the principal parts involved in our invention We shall briefly describe the operation of the same. When it is desired to change the engine from compound to simple the air is admitted to the chamber G forcing the piston and valve in the direction indicated by arroW until the expander ring L10 striking the shoulder 2 of the valve casing and moving longitudinally against the split rings L7, L8, We( ging them against the machine face L2 of the piston and expanding them against the Walls of the casing. It Will be seen that the tighteningof the piston occurs at the end of the stroke of the valve, the piston moves freely in the cas ing during the major portion of its stroke thus avoiding any unnecessary Wear, Which would enlarge at the inner diameter of the casing at any oint and produce a leakage of air Which Wou d decrease the sensitiveness of the valve and be detrimental to the air pump. It will also be seen that should the holding nut of the valve break 0H that it would not affect the Working thereof. Should such a thing occur the head Would be held in place by the air pressure forcing it on the valve rod. The compressionl spring in our construction bears on the nut and therefore does not force the head off the stem as in thc old construction.

It Will be understood that a head such :as described may be used for any purpose Where the pistonWorks from one end and operates a valve or performs Work at the other end.

What We claim as our invention is: v

In a valve of the class described, the combination With the casing, having a shoulder therein intermediate of its length and an air inlet, andthe valve stem7 of a piston head having an enlarged end having an -inclined face, ya Wedge ring surrounding the piston and designed to strike the shoulder formed in the casing7 packing rings having inclined faces corresponding respectively to the inclined faces of the AWedge ring and enlarged end, as and for the purpose speciiied.

ADAM STEWART. JAMES MCCLUSKEY. HERBERT GATES REID. Witnesses:

S. E. BRENNAN, A. F. KNIGHT. 

